This derivation explains how the radius of curvature R at a point on a smooth curve quantifies how sharply the curve bends. For a function y = f(x), the radius of curvature is given by:
R = \frac{[1 + (dy/dx)^2]^{3/2}}{|d^2y/dx^2|}
This formula is derived using concepts from differential geometry and represents the radius of the osculating circle (best-fitting circle) at a given point on the curve.